Post by thread:[PIC]: Interfacing 16F877 to serial eeprom 24WC16

Hi, Piclisters, Could someone of you tell me where I could find the assembly routines to interface a 16F877 and a 24WC16 ? I have had a look at Microchip website and found some Application Notes, but none of them were for the microprocessor and the eeprom I am dealing with ... :-( Thanks ! Joan Ilari Barcelona (Spain) Tel. +34 93 431 96 39 spam_OUTjoanTakeThisOuTilari.org ================================================================ ... I've seen things you people wouldn't believe. Attack ships on fire off the shoulder of Orion. I watched C-beams glitter in the dark near Tannhauser Gate. All those moments will be lost in time, like tears in rain ... Time to die ... -Blade Runner - ================================================================ -- http://www.piclist.com hint: To leave the PICList .....piclist-unsubscribe-requestKILLspam@spam@mitvma.mit.edu

On Wed, May 01, 2002 at 03:33:11PM +0200, Joan Ilari wrote: > Hi, Piclisters, > > Could someone of you tell me where I could find the > assembly routines to interface a 16F877 and a 24WC16 ? > I have had a look at Microchip website and found some > Application Notes, but none of them were for the > microprocessor and the eeprom I am dealing with ... :-( The 24WC16 is a I2C standard EEPROM. The 16F877 can act as a I2C master in software. I was never really clear as to why the master interface could not be incorporated into the hardware I2C module. Anyway take a read of section 17 of the Microchip Midrange Reference Manual titled: MASTER SYNCHRONOUS SERIAL PORT. Also check out chapter 9 of the 16F877 data sheet on the MSSP. Don't get too caught up on the specific chip. The only real differences between 24XXXX type I2C serial EEPROMs are capacity, multichip addressing, and the size of page writes. So any code that either completely bit bangs or uses the MSSP to communicate to a 24XXXX type EEPROM should work for the 24WC16. BAJ -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestKILLspammitvma.mit.edu

> The 24WC16 is a I2C standard EEPROM. The 16F877 can act as a I2C master in > software. I was never really clear as to why the master interface could not > be incorporated into the hardware I2C module. Um, it is. The "M" in MSSP stands for "master". ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList .....piclist-unsubscribe-requestKILLspam.....mitvma.mit.edu

On Wed, May 01, 2002 at 01:47:18PM -0400, Olin Lathrop wrote: > > The 24WC16 is a I2C standard EEPROM. The 16F877 can act as a I2C master in > > software. I was never really clear as to why the master interface could > not > > be incorporated into the hardware I2C module. > > Um, it is. The "M" in MSSP stands for "master". I've located the source of my confusion. I was just starting to look at this process. So I printed chapter 15 of the Midrange manual: the SSP. It doesn't implement master function natively. Thanks for the correction Olin. BAJ -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspam_OUTTakeThisOuTmitvma.mit.edu

> Don't get too caught up on the specific chip. The only real differences between > 24XXXX type I2C serial EEPROMs are capacity, multichip addressing, and the size > of page writes. So any code that either completely bit bangs or uses the MSSP > to communicate to a 24XXXX type EEPROM should work for the 24WC16. 1. Smaller EEPROMS (24c01,02,04,16) use only one byte to indicate the word address when doing page-writes. 2. Larger EEPROMS (24c32, 24c64, ...128?, ...256?, ...512?) use two bytes to indicate word address. So there is a subtle (but very important) difference in the chips and the I2C protocol they use. michael brown -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

>So any code that either completely bit bangs or uses the MSSP >to communicate to a 24XXXX type EEPROM should work for the 24WC16. The address for a eeprom bigger than 24LC16 is two bytes long, while the address for a eeprom equal to 24LC16 or smaller is one byte long. Regards -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads